Mercurial > hg > openttd
changeset 1852:e67817ae950c draft
(svn r2358) Add macros for getting (GB) and setting (SB) a range of bits
Use them exemplarily to prettify (Get|Set)Tile(Type|Height)
author | tron <tron@openttd.org> |
---|---|
date | Sun, 22 May 2005 07:12:09 +0000 |
parents | fc4fffa72c1b |
children | f37c0a881cd8 |
files | macros.h tile.h |
diffstat | 2 files changed, 9 insertions(+), 6 deletions(-) [+] |
line wrap: on
line diff
--- a/macros.h +++ b/macros.h @@ -151,4 +151,9 @@ } #endif +// Fetch count bits starting at bit start from value +#define GB(value, start, count) (((value) >> (start)) & ((1 << (count)) - 1)) +// Set count bits in value starting at bit start to data +#define SB(value, start, count, data) ((value) = ((value) & ~(((1 << (count)) - 1) << (start))) | ((data) << (start))) + #endif /* MACROS_H */
--- a/tile.h +++ b/tile.h @@ -46,15 +46,14 @@ static inline uint TileHeight(TileIndex tile) { assert(tile < MapSize()); - return _map_type_and_height[tile] & 0xf; + return GB(_map_type_and_height[tile], 0, 4); } static inline void SetTileHeight(TileIndex tile, uint height) { assert(tile < MapSize()); assert(height < 16); - _map_type_and_height[tile] &= ~0x0F; - _map_type_and_height[tile] |= height; + SB(_map_type_and_height[tile], 0, 4, height); } static inline uint TilePixelHeight(TileIndex tile) @@ -65,14 +64,13 @@ static inline TileType GetTileType(TileIndex tile) { assert(tile < MapSize()); - return _map_type_and_height[tile] >> 4; + return GB(_map_type_and_height[tile], 4, 4); } static inline void SetTileType(TileIndex tile, TileType type) { assert(tile < MapSize()); - _map_type_and_height[tile] &= ~0xF0; - _map_type_and_height[tile] |= type << 4; + SB(_map_type_and_height[tile], 4, 4, type); } static inline bool IsTileType(TileIndex tile, TileType type)